Intravenous Glucose Infusion Research Articles

Low availability of haematin (hemin) in Pakistan

Madam, Acute Intermittent Porphyria (AIP) is an autosomal dominant disorder that results from a defect in the enzyme named porphobilinogen deaminase.1 It is symptomatic porphyria, involving the accumulation of porphyrins and porphyrin precursors due to impaired conversion in haeme synthesis. Acute Intermittent Porphyria is clinically characterized by acute episodes of multiple gastrointestinal and neurologic symptoms; during which the patient remains healthy between episodes.2 Acute Intermittent Porphyria episodes are commonly observed in post pubertal females. The most common symptoms include periodic abdominal pain, vomiting and hypertension followed by neurologic damage that leads to peripheral and autonomic neuropathies (mostly motor) and psychiatric manifestations.2 Hormonal cycle regulation may worsen porphyria, since its symptoms coincide with the menstrual cycle. Although positive response has been noted in hormonal suppression by gonadotropin releasing hormone agonists.3 Currently, the most widely used treatment is hemin, a form of haeme that can be given intravenously. Its administration reduces the haeme deficit, hence limits the production of porphyrins precursors by the body. Availability of hemin in Pakistan is not promising while alternatives such as intravenous infusion of glucose, and pain relievers like Nalbuphine, a man-made opioid analgesic, and Morphine are short-term treatments. Haeme Arginate (HA), a compound of haeme and arginine, is equivalent to hematin in the treatment of AIP. Long-term weekly intravenous infusions of prophylactic HA prevent severity and frequency of porphyric attacks in patients with AIP.4 While haeme therapy is recommended if a patient exhibits neurological impairment, liver transplant appears to be the last resort in patients with recurrent clinical manifestations. To effectively mediate the growing need of Hemin in Pakistan, a systematic plan with effective and immediate steps must be introduced. The regulatory authorities must expedite the approval and licensing process of appropriate medication that would meet the growing need of the country, while not compromising on its quality. The possibility of local production should be explored, while strengthening international ties aimed at importing affordable medication. The government should focus on initiating partnerships with international organizations, non-governmental organizations (NGOs) and global health initiatives. Nationwide workshops and informative campaigns towards healthcare work should be a priority, to raise awareness of the situation and the proper steps that should be taken to minimize its adverse effects. Empowering patient advocacy groups would be beneficial in recognizing any shortcomings of the plan and to divert resources accordingly.

8255 Munchausen Syndrome After Partial Pancreatectomy for Insulinoma: A Case Report

Abstract Disclosure: C.R. de Macedo: None. T.D. Bertolacini da Silva: None. I.P. de Magalhães: None. M.A. Pereira: None. I.C. Marques: None. J.L. Pinheiro Filho: None. G.F. Darce: None. D.M. Lourenço Junior: None. Background: Insulinoma is a rare, insulin-secreting pancreatic neuroendocrine tumor, most commonly benign, solitary, sporadic, well differentiated and with a slight female predominance. The investigation of hypoglycemia requires a fasting test to exclude, among other causes, factitious hypoglycemia. Clinical Case: A 27-year-old woman was admitted to the emergency room after seizure by hypoglycemic crisis (capillary blood glucose < 55 mg/dL). She had recurrent episodes of adrenergic/neuroglycopenic symptoms since the age of 14, occurring during fasting, mainly in the morning, with improvement after eating. After confirming Whipple's triad, a fasting test showed hyperinsulinemic hypoglycemia (glycemia 53 mg/dL, normal value >55 mg/dL; insulin 11.5 mcU/mL, nv <3mcU/mL) and increased C-peptide (3.83 ng/mL, nv <0,6 ng/mL). Abdominal magnetic resonance showed a 1.4 cm nodule in the pancreas tail. During hospitalization, she experienced Raynaud's phenomenon, leading to the diagnosis of Raynaud's disease (RD). Distal pancreatectomy was performed, confirming the diagnosis of insulinoma by immunohistochemistry. There was brief remission of the hypoglycemic episodes once they recurred two weeks later. As imaging tests did not show new pancreatic lesions, somatostatin analogue was begun, resulting in improvement for a few more weeks. Due to recurrent hypoglycemia and new seizures, she required continuous intravenous infusion of glucose during hospitalization. A new fasting test revealed hyperinsulinemic hypoglycemia (glycemia 42 mg/dL, insulin 43.3 mcU/mL), low C-peptide (0.5 ng/mL) and normal proinsulin (2.39 pmol/L, nv <5 pmol/L) values. Due RD, auto-immune hypoglycemia was excluded by negative anti-insulin antibodies. Insulinomatosis was also considered, as potential etiology, but review of surgical specimen excluded this hypothesis. After 4 months of hospitalization, due suspicious behavior, a review of her personal belongings revealed insulin vials and needles for injection. The patient confessed to applying insulin to simulate the symptoms, also revealing a history of childhood trauma and previous suicide attempts. After psychiatric evaluation, borderline personality disorder was identified, and Munchausen syndrome was considered. Since then, the patient did not require intravenous glucose with no recurrence of hypoglycemia. Conclusion: The investigation of hypoglycemia can be challenging, requiring appropriate diagnostic protocols. Even in patients who appear to have a well-defined diagnosis, as in our case with anatomopathological confirmation of insulinoma, it is always important to rule out factitious hypoglycemia. The incorrect diagnosis can lead to inappropriate invasive and surgical procedures with definitive consequences, such as exogenous pancreatic insufficiency and insulin-dependent diabetes mellitus. Presentation: 6/1/2024

6611 ACTH deficiency due to TBX19 mutation mimics complete adrenal insufficiency in a newborn

Abstract Disclosure: T. Reinehr: None. P.M. Holterhus: None. S.A. Wudy: None. A. Richter-Unruh: None. C. Spratte: None. C. Roll: None. Isolated ACTH deficiency (IAD) is a rare cause of adrenocortical insufficiency. T-box transcription factor 19 (TBX19) mutations are responsible for more than 60% of neonatal cases of IAD. To the best of our knowledge, we present for the first time a newborn with ACTH deficiency due to a TBX19 mutation with almost steroid-free plasma and urine: At day 2 of life, the female newborn (birth weight 3190g, length 52 cm, 40+1 gestational age) was transferred to our neonatal intensive care unit for severe hypoglycemia (12 mg/dl), which responded to intravenous glucose infusion. Surprisingly, the sodium serum concentrations decreased from 140 mmol/l at day 2 of life to 126 mmol/l at day 7 of life. There were no clinical signs of adrenal insufficiency such as vomiting or hypotonia. Treatment with oral sodium-chloride 5.85% was started. Endocrine diagnostic work-up performed at day 8 of life demonstrated normal values of fT4, HGH and IGFBP-3 ruling out pituitary involvement of these axes, while ACTH serum concentrations were markedly decreased (1.5 pg/ml). Liquid- chromatography-mass spectrometry (LC-MS/MS) revealed nearly absent glucocorticoids (17-hydroxyprogesterone <0.12 nmol/l, 11-deoxycortisol <0.08 nmol/l, cortisol <4.2 nmol/l, and cortisone 1.3 nmol/l (norm value [nv]: 17-138 nmol/l)). Androgens were undetectable (testosterone <0.02 nmol/l, androstenedione <0.08 nmol/l). Mineralocorticoids were severely reduced (11-desoxycorticosterone 0.1 nmol/l (nv: 0.2-1.0 nmol/l), corticosterone 0.6 nmol/l (nv: 1-24 nmol/l), aldosterone 0.1 nmol/l (nv: 0.8-2.3 nmol/l)). In urine spot, gas chromatography-mass spectrometry (GC-MS) demonstrated subnormal excretion of C19 and C21 steroids including fetal zone steroids. Serum and urine measurements were interpreted by the labs as a typical finding similar to StAR defect. The genetic analyses revealed a normal female karyotype (46,XX) and ruled out CYP11A1 and StAR, mutations but demonstrated a homozygous missense mutation in TBX19 (c.172A>G, p.(Thr58Ala)). After 3 months of life under treatment with hydrocortisone (10mg/m² divided in 3 doses) and fludrocortisone (0.05 mg divided in 2 doses), cortisol was normal (320 nmol/l) and DHEAS was undetectable (<3 nmol/l). While androgens were in normal range (testosterone 2.6 nmol/l, androstenedione 0.28 nmol/l), 11-deoxycorticosterone was normal (0.74 nmol/l), corticosterone was undetectable (<0.5 nmol/l) and aldosterone was decreased (0.12 nmol/l nv: 0.8-1.2 nmol/l). At this time point, ACTH was <4 pg/ml, renin 1.6 mIU/l, LH 0.7 mIU/l and FSH 24.5 mIU/ml. This case demonstrated that isolated ACTH deficiency should be considered as a potential differential diagnosis in complete adrenal steroid insufficiency in newborns. Our data suggest that ACTH is not only necessary for cortisol biosynthesis but also for sufficient mineralocorticoid and androgen production by the adrenals in neonates. Presentation: 6/3/2024

The incretin effect in type 2 diabetes in a Sub-Saharan African population

AimType 2 diabetes is increasing in Sub-Saharan Africa, but the pathophysiology in this population is poorly investigated. In Western populations, the incretin effect is reduced in type 2 diabetes, leading to lowered insulin secretion. The aim of this study was to investigate the incretin effect in a group of Sub-Saharan Africans with type 2 diabetes.MethodsTwenty adults diagnosed with type 2 diabetes, based on either an oral glucose tolerance test (n = 10) or on glycated hemoglobin A1c (n = 10), and 10 non-diabetic controls were included in an interventional study in Tanzania. We investigated the incretin effect as the difference between the plasma insulin area under the curve during an oral glucose tolerance test and that obtained during an intravenous glucose infusion. Differences between diabetes groups were analyzed by Kruskal–Wallis one-way analysis of variance.ResultsThe incretin effect did not differ between groups (p = 0.45), and there was no difference in plasma concentrations of the incretin hormones during the OGTT.ConclusionA reduced incretin effect appears not to contribute to hyperglycemia in type 2 diabetes in this Tanzanian population. More research is needed to explain the diabetes phenotype often seen in Sub-Saharan Africa.Trial registrationClinicaltrials.gov: NCT03106480, date of registration: 04/10/2017.

Unraveling a Novel Mechanism of Altered Glomerular Hemodynamics in Pre-diabetic Obesity

Background: In pre-diabetic obesity, disrupted glomerular autoregulation leads to increased glomerular capillary pressure and renal blood flow, causing potential barotrauma-induced glomerular damage. A decrease in Afferent arteriole ( Af-Art) resistance causes higher glomerular capillary pressure but the underlying mechanism behind this, specifically in pre-diabetic obesity, remains unclear. Hyperinsulinemia is common in pre-diabetic obesity, but its role in reducing Af-Art resistance in the kidneys is unknown. Kidney blood flow is auto-regulated by vasoconstriction via tubuloglomerular feedback (TGF) and vasodilation through the Distal convoluted tubule-2/connecting tubule (DCT-2/CNT) mechanism. Our earlier studies indicate increased Af-Art dilation in pre-diabetic obese rats through the DCT-2/CNT mechanism without affecting TGF. This DCT-2/CNT induced Af-Art dilation requires initiation from epithelial sodium channels (ENaC) present at this tubular segment and interestingly insulin is a known ENaC activator. Hypothesis: We hypothesize that in the context of pre-diabetic obesity, hyperinsulinemia contributes to an increase in renal cortical blood flow (CBF) by increasing DCT-2/CNT-induced Af-Art dilation, subsequently leading to glomerular injury. Methods: We assessed the effects of insulin on Af-Art dilation by perfusing juxtaposed DCT-2/CNT segments with insulin in normal rabbits. Contribution of DCT-2/CNT induced Af-Art dilation was measured by co-administration of the ENaC blocker benzamil. To study hyperinsulinemia's role in an in-vivo setting without altering blood glucose levels, we used a hyperinsulinemic-euglycemic (HI-EUG) clamp in obese rats with intravenous (IV) glucose and insulin infusions. Renal CBF and blood pressure were monitored using a laser Doppler probe and femoral artery catheter, respectively, both with and without benzamil administration (400 μg/kg, IV). To evaluate insulin's potential role in causation of renal damage, we infused insulin directly into one kidney of lean rats for 6 weeks via a renal sub-capsular catheter, with the contralateral kidney serving as control. Glomerular basement membrane (GBM) thickness, a marker of renal damage, was measured via electron microscopy. Untargeted lipidomic analysis of the renal cortex was performed to identify potential renal damage pathways in insulin infused kidneys. Results: Insulin perfusion in rabbits' DCT-2/CNT potentiated the dilation of adherent Af-Art compared to control infusions with artificial tubular fluid. ENaC inhibition reversed the insulin-induced Af-Art dilation, confirming that insulin increases Af-Art dilation through the ENaC-initiated DCT-2/CNT mechanism. In obese rats, insulin delivery using a HI-EUG clamp resulted in a significant 20.8±4.9% increase in CBF, which was negated by the administration of the ENaC blocker benzamil, indicating the potential involvement of DCT-2/CNT-mediated vasodilation. Neither the HI-EUG clamp nor benzamil infusion affected blood pressure. Additionally, continuous direct insulin infusion into the kidneys of lean rats led to an increase in glomerular basement membrane (GBM) thickness and ceramide accumulation in the renal cortex, both indicative of renal damage. Conclusion: Our study demonstrates that insulin directly augments DCT-2/CNT-mediated Af-Art dilation and increases renal cortical blood flow in obese rats. Chronic renal insulin infusion led to structural changes and damage markers in the kidney, independent of blood glucose and blood pressure levels. Henry Ford Health System Internal Funding. Pilot and Feasibility grant from southeast center for integrated metabolomics. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Serum osteoglycin is stable during various glycemic challenges in healthy men

PurposeOsteoglycin is hypothesized to be metabolically active and may enhance insulin action. We hypothesized that osteoglycin levels increase during hyperglycemia as a physiological response to enhance the effects of insulin.MethodsEight healthy males were included in a cross-over study consisting of three study days following an 8 h fast. First, we performed an oral glucose tolerance test (OGTT); second, an isoglycemic intravenous glucose infusion (IIGI); and third, a control period consisting of a three hour fast. We analyzed blood samples for circulating osteoglycin levels during the study days. Repeated measures ANOVA was performed to compare levels of s-osteoglycin between OGTT, IIGI, and the fasting control.ResultsThere were no differences in baseline osteoglycin levels among study days (p > 0.05). We observed no significant changes neither in absolute s-osteoglycin levels by time (p = 0.14) nor over time by study day (p = 0.99). Likewise, we observed no significant changes in percentage s-osteoglycin levels neither by time (p = 0.11) nor over time by study day (p = 0.89).ConclusionWe found that s-osteoglycin levels were stable for three hours during OGTT, IIGI, and fasting in healthy males. Based on the present study, circulating s-osteoglycin levels may be measured independently of fasting or non-fasting conditions. Furthermore, circulating physiological levels of glucose and insulin did not affect s-osteoglycin levels.

An extended minimal model of OGTT: estimation of α- and β-cell dysfunction, insulin resistance, and the incretin effect.

Loss of insulin sensitivity, α- and β-cell dysfunction, and impairment in incretin effect have all been implicated in the pathophysiology of type 2 diabetes (T2D). Parsimonious mathematical models are useful in quantifying parameters related to the pathophysiology of T2D. Here, we extend the minimum model developed to describe the glucose-insulin-glucagon dynamics in the isoglycemic intravenous glucose infusion (IIGI) experiment to the oral glucose tolerance test (OGTT). The extended model describes glucose and hormone dynamics in OGTT including the contribution of the incretin hormones, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide-1 (GLP-1), to insulin secretion. A new function describing glucose arrival from the gut is introduced. The model is fitted to OGTT data from eight individuals with T2D and eight weight-matched controls (CS) without diabetes to obtain parameters related to insulin sensitivity, β- and α-cell function. The parameters, i.e., measures of insulin sensitivity, a1, suppression of glucagon secretion, k1, magnitude of glucagon secretion, γ2, and incretin-dependent insulin secretion, γ3, were found to be different between CS and T2D with P values < 0.002, <0.017, <0.009, <0.004, respectively. A new rubric for estimating the incretin effect directly from modeling the OGTT is presented. The average incretin effect correlated well with the experimentally determined incretin effect with a Spearman rank test correlation coefficient of 0.67 (P < 0.012). The average incretin effect was found to be different between CS and T2D (P < 0.032). The developed model is shown to be effective in quantifying the factors relevant to T2D pathophysiology.NEW & NOTEWORTHY A new extended model of oral glucose tolerance test (OGTT) has been developed that includes glucagon dynamics and incretin contribution to insulin secretion. The model allows the estimation of parameters related to α- and β-cell dysfunction, insulin sensitivity, and incretin action. A new function describing the influx of glucose from the gut has been introduced. A new rubric for estimating the incretin effect directly from the OGTT experiment has been developed. The effect of glucose dose was also investigated.

Rectal sensitivity correlated with gastrointestinal-mediated glucose disposal, but not the incretin effect.

The mechanisms behind the diminished incretin effect in type 2 diabetes are uncertain, but impaired vagal transmission has been suggested. We aimed to investigate the association between the incretin effect and autonomic neuropathy, and the degree of dysglycaemia and duration of diabetes. For a cross-sectional study, we included participants with either longstanding type 2 diabetes, recent onset, untreated diabetes and controls without diabetes matched for age, sex and body mass index. Autonomic nerve function was assessed with cardiovascular reflex tests, heart rate variability and sudomotor function. Visceral afferent nerves in the gut were tested performing rapid rectal balloon distention. An oral glucose tolerance test and an intravenous isoglycaemic glucose infusion were performed to calculate the incretin effect and gastrointestinal-mediated glucose disposal (GIGD). Sixty-five participants were recruited. Participants with diabetes had rectal hyposensitivity for earliest sensation (3.7 ± 1.1 kPa in longstanding, 4.0 ± 1.3 in early), compared to controls (3.0 ± 0.9 kPa), p = .005. Rectal hyposensitivity for earliest sensation was not associated with the incretin effect (rho = -0.204, p = .106), but an association was found with GIGD (rho -0.341, p = .005). Incretin effect and GIGD were correlated with all glucose values, HbA1c and duration of diabetes. Rectal hyposensitivity was uncovered in both longstanding and early type 2 diabetes, and was not associated with the incretin effect, but with GIGD, implying a potential link between visceral neuropathy and gastrointestinal handling of glucose. Both the incretin effect and GIGD were associated with the degree of dysglycaemia and the duration of diabetes. Some of the data have previously been published and presented as a poster on the American Diabetes Association 83rd Scientific Sessions: Meling etal; 1658-P: Rectal Hyposensitivity, a Potential Marker of Enteric Autonomic Nerve Dysfunction, Is Significantly Associated with Gastrointestinally Mediated Glucose Disposal in Persons with Type 2 Diabetes. Diabetes 20 June 2023; 72 (Supplement_1): 1658-P. https://doi.org/10.2337/db23-1658-P.

Incretin effect determines glucose trajectory and insulin sensitivity in youths with obesity.

In youths with obesity, the gut hormone potentiation of insulin secretion - the incretin effect - is blunted. We explored the longitudinal impact of the incretin effect during pubertal transition on β cell function and insulin sensitivity. Youths with obesity and 2-hour glucose level ≥ 120 mg/dL underwent a 3-hour oral glucose-tolerance test (OGTT) and an isoglycemic i.v. glucose infusion to quantify the incretin effect. After 2 years, 30 of 39 participants had a repeated OGTT and were stratified into 3 tertiles according to the baseline incretin effect. The high-incretin effect group demonstrated a longitudinal increase in β cell function (disposition index, minimal model [DIMM]), with greater insulin sensitivity at follow-up and stable insulin secretion (φtotal). A lower incretin effect at baseline was associated with higher 1-hour and 2-hour glucose level at follow-up. The high-incretin effect group displayed a greater increase of GLP-17-36 than the moderate- and low-incretin group at baseline, while such a difference did not persist after 2 years. Glucagon suppression was reduced at follow-up in those with low-baseline incretin in respect to the high-incretin group. The incretin effect during pubertal transition affected the longitudinal trajectory of β cell function and weight in youths with obesity.

Liraglutide treatment for the prevention of glucose tolerance deterioration in women with prior gestational diabetes mellitus: A 52-week randomized controlled clinical trial.

We investigated the effect of 52-week treatment with liraglutide, a glucagon-like peptide 1 receptor agonist, on glucose tolerance and incretin effect in women with previous gestational diabetes mellitus (pGDM). Women with overweight/obesity and pGDM were randomized to once daily subcutaneous liraglutide 1.8 mg or placebo for 52 weeks. Participants underwent oral glucose tolerance test (OGTT) and isoglycaemic intravenous glucose infusion at baseline and at 52 weeks, and an additional OGTT after the drug wash-out. In total, 104 women [age: mean ± SD, 38 ± 5 years; fasting plasma glucose (FPG): 5.5 ± 0.4 mmol/L; glycated haemoglobin (HbA1c): 33 ± 4 mmol/mol, bodyweight: 88.2 ± 14.8 kg, body mass index: 31.1 ± 4.3 kg/m2 ] were assigned to liraglutide (n = 49) or placebo (n = 55). Estimated treatment difference (ETD) for area under curve during OGTT was -173 (95% confidence interval -250 to -97) mmol/L × min, p < .0001, but after wash-out the difference disappeared [ETD 58 (-30 to 146) mmol/L × min, p = .536]. Liraglutide reduced FPG [ETD -0.2 (-0.4 to -0.1) mmol/L, p = .018], HbA1c [-2.2 (-3.5 to -0.8) mmol/mol, p = .018] and bodyweight [-3.9 (-6.2 to -1.6) kg, p = .012]. No change in the incretin effect was observed. The number of women with prediabetes was reduced from 64% to 10% with liraglutide vs. 50% with placebo [adjusted odds ratio 0.10 (0.03-0.32), p = .002]. Treatment with liraglutide for 52 weeks improved glucose tolerance, FPG, HbA1c and bodyweight in women with overweight/obesity and pGDM. Progression to prediabetes while on drug was markedly reduced, but after a 1-week drug wash-out, the effect was lost.

Effect of glucose infusion on glucose and insulin metabolism in early- and mid-lactation ewes and goats fed diets differing in starch and highly digestible fiber concentration

This study aimed to test possible metabolic differences between ewes and goats in response to an intravenous glucose infusion. Thirty-six animals, 18 mature Sarda dairy ewes and 18 mature Saanen goats (from 15 to 150 ± 11 d in milk [DIM], mean ± SD; body weight: 49.8 ± 6.8 kg for ewes, 60.6 ± 7.3 kg for goats) were compared simultaneously. In early lactation, both species received the same high-starch diet (HS: 20.4% starch, 35.4% neutral detergent fiber [NDF], on dry matter [DM] basis), whereas from 92 ± 11 DIM both species were randomly allocated to 2 dietary treatments: HS (20.0% starch, 36.7% NDF, on DM basis) and low-starch (LS: 7.8% starch, 48.8% NDF, on DM basis) diets. At 50 and 150 ± 11 DIM, ewes and goats were challenged with an intravenous glucose tolerance test and peripheral concentrations of glucose and insulin were determined 15 min before and 5, 10, 15, 30, 45, 90, and 180 min after glucose infusion. In early lactation, baseline plasma glucose and insulin concentrations tended to be higher in ewes than in goats (glucose: 55.8 vs. 42.9 ± 7.3 mg/dL; insulin: 0.13 vs. 0.05 ± 0.04 µg/L). After glucose infusion, glucose and insulin concentrations were higher in ewes than in goats (278.6 vs. 247.6 ± 13.1 mg/dL; 0.82 vs. 0.46 ± 0.12 µg/L). In mid-lactation, the dietary treatment (HS vs. LS) did not affect glucose and insulin metabolism. Baseline plasma glucose was numerically highest in ewes, while baseline insulin was higher in ewes than in goats (0.39 vs. 0.12 ± 0.099 µg/L). After glucose infusion, glucose concentration did not differ between ewes and goats, while insulin concentration was highest in ewes. Compared with goats, ewes showed in both periods a higher peak insulin, insulin increment, linear insulin area under the curve, insulin resistance index, and lower insulin sensitivity indices. In conclusion, despite the limitations associated with the use of intravenous glucose tolerance test to assess glucose regulation mechanisms, this study indicated large species differences in both early and mid-lactation and a more evident anabolic status in the ewes compared with the goats.

Factors Associated with Need for Intravenous Glucose Infusion for the Treatment of Early Neonatal Hypoglycemia in Late Preterm and Term Neonates.

The aim of this study was to determine which late-preterm (35-36 weeks' gestational age [GA]) and term neonates with early-onset hypoglycemia in the first 72 hours postnatal required a continuous glucose infusion to achieve and successfully maintain euglycemia. This is a retrospective cohort study of late preterm and term neonates born in 2010-2014 and admitted to the Mother-Baby Unit at Parkland Hospital who had laboratory-proven blood glucose concentration < 40 mg/dL (2.2 mmol/L) during the first 72 hours of life. Among the subgroup needing intravenous (IV) glucose infusion, we analyzed which factors predicted a maximum glucose infusion rate (GIR) ≥ 10 mg/kg/min. The entire cohort was randomly divided into a derivation cohort (n = 1,288) and a validation cohort (n = 1,298). In multivariate analysis, the need for IV glucose infusion was associated with small size for GA, low initial glucose concentration, early-onset infection, and other perinatal variables in both cohorts. A GIR ≥ 10 mg/kg/min was required in 14% of neonates with blood glucose value < 20 mg/dL during the first 3 hours of observation. The likelihood of a GIR ≥ 10 mg/kg/min was associated with lower initial blood glucose value and lower umbilical arterial pH. Need for IV glucose infusion was associated with small size for GA, low initial glucose concentration, early-onset infection, and variables associated with perinatal hypoxia-asphyxia. The likelihood of a maximum GIR ≥ 10 mg/kg/min was greater in neonates with lower blood glucose value during the first 3 hours of observation and lower umbilical arterial pH. · We studied 51,973 neonates ≥ 35 weeks' GA.. · We established a model predicting the need for IV glucose.. · We also predicted the need for a high rate of IV glucose..

Signs of a Glucose- and Insulin-Independent Gut-Bone Axis and Aberrant Bone Homeostasis in Type 1 Diabetes.

Gut hormones seem to play an important role in postprandial bone turnover, which also may be affected by postprandial plasma glucose excursions and insulin secretion. To investigate the effect of an oral glucose tolerance test (OGTT) and an isoglycemic intravenous glucose infusion (IIGI) on bone resorption and formation markers in individuals with type 1 diabetes and healthy controls. This observational case-control study, conducted at the Center for Clinical Metabolic Research, Gentofte Hospital, Hellerup, Denmark, included 9 individuals with C-peptide negative type 1 diabetes and 8 healthy controls matched for gender, age, and body mass index. Subjects underwent an OGTT and a subsequent IIGI. We analyzed changes in bone resorption assessed by measurements of carboxy-terminal type I collagen crosslinks (CTX) and in bone formation as assessed by procollagen type I N-terminal propeptide (PINP) concentrations. Baseline CTX and PINP levels were similar in the 2 groups. Both groups exhibited significantly greater suppression of CTX during OGTT than IIGI. PINP levels were unaffected by OGTT and IIGI, respectively, in healthy controls. Participants with type 1 diabetes displayed impaired suppression of CTX-assessed bone resorption and inappropriate suppression of PINP-assessed bone formation during OGTT. Our data suggest the existence of a gut-bone axis reducing bone resorption in response to oral glucose independently of plasma glucose excursions and insulin secretion. Subjects with type 1 diabetes showed impaired suppression of bone resorption and reduced bone formation during OGTT, which may allude to the reduced bone mineral density and increased fracture risk characterizing these individuals.

A case of frequent hypoglycemic attacks successfully controlled with capecitabine plus temozolomide and 177Lu-DOTATATE peptide receptor radionuclide therapy in a patient with recurrent pancreatic insulinoma.

A 59-year-old woman with metastatic pancreatic insulinoma, having undergone several treatment regimens including sunitinib, everolimus, lanreotide and streptozocin plus 5-fluorouracil, was admitted to our hospital because of frequent hypoglycemic attacks. These were refractory to medical treatment using diazoxide and required frequent daily intravenous glucose infusions. She was started on capecitabine and temozolomide (CAPTEM), followed by initiation of 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). The frequency of hypoglycemic attacks decreased after treatment began and she was discharged on day 58 post-admission, without requiring daily glucose infusions. CAPTEM and PRRT were continued without any major adverse events. Computed tomography revealed shrinkage of primary and metastatic lesions, an anti-tumor effect that continued 8months after treatment was initiated. Hypoglycemic attacks caused by insulinomas are often refractory to conventional therapy; however, combination treatment using CAPTEM and PRRT has demonstrated a positive and significant response, successfully restoring glycemic control.

1658-P: Rectal Hyposensitivity, a Potential Marker of Enteric Autonomic Nerve Dysfunction, Is Significantly Associated with Gastrointestinally Mediated Glucose Disposal in Persons with Type 2 Diabetes

The incretin effect in type 2 diabetes is reduced, but the mechanisms behind are uncertain. We hypothesized that the incretin effect associates with degree of enteric autonomic nerve dysfunction and evaluated gastrointestinally mediated glucose disposal (GIGD), as a proxy for the incretin effect, and rectal sensitivity to mechanical distension representing afferent gut signalling. Sixty-six participants with either 1) longstanding type 2 diabetes, 2) newly onset (&amp;lt;1 year), medically untreated diabetes, or 3) healthy controls, underwent a 75 g oral glucose tolerance test (OGTT) and an intravenous isoglycemic glucose infusion to determine GIGD. Earliest sensation to rectal rapid balloon distention was determined as a proxy for autonomic neuropathy. Compared to controls (59.3±14.4%), GIGD was reduced in both early (36.4±14.7%) and longstanding diabetes (17.4±22.3%), with significant difference between all three groups (P&amp;lt;0.01). Both groups of diabetes needed higher pressure during rapid rectal balloon distention (3.7±1.1 kPa for longstanding diabetes, 4.0±1.3 for early diabetes), compared to controls (3.0±0.9 kPa, P&amp;lt;0.01), with no significant difference between the two diabetes groups. GIGD was inversely correlated with pressure at earliest sensation (rho 0.341, P&amp;lt;0.01). For those needing a pressure between 1 and 3 kPa and between 4 and 7 kPa, respectively, GIGD was 46.2%±24.9 and 34.4±23.9% (P=0.05). GIGD was inversely and significantly correlated with glucose values during OGTT, with strongest correlation to the 90-minute value (rho 0.873, P&amp;lt;0.01), and HbA1c (rho 0.653, P&amp;lt;0.01). We show that the degree of rectal hyposensitivity correlates with reduced GIGD and confirm that GIGD correlates with the degree of dysglycemia. These results warrant further studies on the potential role of gut autonomic dysfunction in the reduced incretin effect characterizing type 2 diabetes. Disclosure S.Meling: Consultant; Novo Nordisk, Lilly, AstraZeneca, Boehringer-Ingelheim, Sanofi. E.Tjora: None. N.Ejskjaer: None. S.Carlsen: None. F.K.Knop: Advisory Panel; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk, Sanofi, Consultant; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk, Sanofi, Research Support; Novo Nordisk, Zealand Pharma A/S, Speaker's Bureau; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk, Sanofi, Lundbeck. P.Njølstad: None. C.Brock: Research Support; Abbott, ElectroCore. R.B.Nedergaard: Other Relationship; Grünenthal Group. E.Søfteland: None. Funding Helse Vest, Norway (F-11637/4800002072); Johan Selmer Kvanes Legat (Legacy)

112-LB: Proof-of-Concept Testing of an Artificial Intelligence–Based Fully Closed-Loop System in Hospitalized Patients with Diabetes

Objective: Achieving tight glucose control safely and effectively is challenging in the Intensive Care Unit (ICU). We conducted the first-in-human test of an artificial intelligence (AI)-based fully autonomous glucose control system in a simulated ICU setting. Methods: We admitted seven participants with type1 and type 2 (n=6) diabetes mellitus for 24-hour closed-loop glucose control sessions that included three unannounced meals. The AI-based system uses glucose control software that controls intravenous insulin and glucose infusions based on real-time continuous glucose monitoring derived data from two real-time CGM devices. The primary efficacy endpoint was the percentage of glucose values within the range of 70-180 mg/dL. The primary safety endpoint was the percentage of glucose values &amp;lt; 70 mg/dL. Results: Participants were on average 48±9.7 years-old, 71% female, and BMI 36±7.8 m/kg2. Mean time in the target range (70-180 mg/dl) was 87.8%. Mean time in the hypoglycemic range (&amp;lt; 70 mg/dL) was 0.2%, Figure. No adverse events occurred. Conclusion: This first in-human results show this novel fully autonomous closed-loop glucose control system designed for the ICU setting has the potential to achieve unparalleled glycemic control with minimal risk of hypoglycemia and paves the way for further research in the actual ICU setting. Disclosure F. Zahedi tajrishi: None. F. J. Pasquel: Consultant; Dexcom, Inc., Medscape, Research Support; Dexcom, Inc., Ideal Medical Technologies. G. Davis: Consultant; Medscape, Research Support; Insulet Corporation. M. Perez-guzman: None. L. I. Guerrero arroyo: None. G. Blanco: None. J. Varghese: None. S. Zahid: None. J. Dejournett: Stock/Shareholder; Ideal Medical Technologies. L. Dejournett: Employee; Ideal Medical Technologies. Funding Ideal Medical Technologies; Dexcom, Inc.

213-LB: Impact of Alpha- and Beta-Cell Dysfunction on the Longitudinal Progression to Type 2 Diabetes

T2D results from glucotoxicity-driven impairment of insulin secretion which limits compensation for increased insulin demand. Increased demand results from insulin resistance and elevated hepatic glucose production (HGP). Increased HGP can result either from insulin resistance or alpha-cell dysregulation leading to hyperglucagonemia. Objectives: To investigate with a mathematical model whether increased HGP and progression to T2D could result from impaired glucagon secretion in addition to insulin resistance. Toward this end, we developed a realistic model of beta-cell growth, death and function and interfaced it with a previously validated model of glucose-insulin-glucagon dynamics. Methods: A previously published model of longitudinal progression to T2D over years was extended to include glucagon dynamics. The beta cell mass/function equation was parametrized by interfacing with results from a previously published paper on modeling isoglycemic, intravenous glucose infusion tests to obtain snapshots of the metabolic state. The range of parameters observed in the cohort studied cover the gamut from normal, insulin sensitive to normal, insulin resistant to T2D patients, and was used to calibrate the model. The influence of insulin resistance and impaired glucagon secretion as they develop over time was included in the combined model to see how they impact the balance between enhanced and impaired beta-cell function and mass. Results and Conclusion: When only insulin sensitivity was allowed to decrease, the normal subjects did not transition to T2D. This was because the glucose levels were not elevated sufficiently to upset the balance between enhancement and impairment and lead to a catastrophic decline in insulin secretion. Including time-dependent impairment of glucagon suppression, in addition to declining insulin sensitivity, was sufficient to lead to the significant imbalance required to progress to T2D diabetes. Thus, both appear to be required. Disclosure V. Subramanian: None. A. Sherman: None. Funding National Institute of Diabetes and Digestive and Kidney Diseases (DK131328)

Copper decorated polyaniline nanowires: A tow-step electrochemical synthesis and a development of a non-enzymatic electrochemical glucose sensor

In this work, a nanostructured electrode material based on copper metal decorated polyaniline nanowires (PANi NWs@Cu) was directly fabricated on a Pt (Pt/PANi NWs@Cu) microelectrode using a novel and effective two-step electrochemical procedure. Herein, the polyaniline nanowires were firstly electropolymerized on the Pt microelectrode using a cyclic voltammetry method, and the copper metal coated onto the polyaniline nanowires were fabricated via a chronoamperometry deposition to form the PANi NWs@Cu with an average diameter of 85 nm. The electrocatalytic activity showed that the as-synthesized PANi NWs@Cu can directly oxidize glucose in alkaline medium, which suggested that the PANi NWs@Cu can be applied as an artificial enzyme for development of a non-enzymatic electrochemical glucose sensor. Obtained results exhibits that the Pt/PANi NWs@Cu has the ability to directly detect glucose with a rapid response, high selectivity, good repeatability, excellent stability with a wide linear range of glucose concentration from 0.5 mM to 50.0 mM and a low detection limit of 94 μM. The developed Pt/PANi NWs@Cu-based electrochemical sensor also shows the ability to directly detect glucose in a 5% glucose intravenous infusion sample with an error of 1.21% from a labelled value.

Hypothalamic Reactivity and Connectivity following Intravenous Glucose Administration.

Dysfunctional glucose sensing in homeostatic brain regions such as the hypothalamus is interlinked with the pathogenesis of obesity and type 2 diabetes mellitus. However, the physiology and pathophysiology of glucose sensing and neuronal homeostatic regulation remain insufficiently understood. To provide a better understanding of glucose signaling to the brain, we assessed the responsivity of the hypothalamus (i.e., the core region of homeostatic control) and its interaction with mesocorticolimbic brain regions in 31 normal-weight, healthy participants. We employed a single-blind, randomized, crossover design of the intravenous infusion of glucose and saline during fMRI. This approach allows to investigate glucose signaling independent of digestive processes. Hypothalamic reactivity and connectivity were assessed using a pseudo-pharmacological design and a glycemia-dependent functional connectivity analysis, respectively. In line with previous studies, we observed a hypothalamic response to glucose infusion which was negatively related to fasting insulin levels. The observed effect size was smaller than in previous studies employing oral or intragastric administration of glucose, demonstrating the important role of the digestive process in homeostatic signaling. Finally, we were able to observe hypothalamic connectivity with reward-related brain regions. Given the small amount of glucose employed, this points toward a high responsiveness of these regions to even a small energy stimulus in healthy individuals. Our study highlights the intricate relationship between homeostatic and reward-related systems and their pronounced sensitivity to subtle changes in glycemia.

Intra-arterial verapamil improves functional outcomes of thrombectomy in a preclinical model of extended hyperglycemic stroke.

The abrupt hyperglycemic reperfusion following thrombectomy has been shown to harm the efficacy of the intervention in stroke patients with large vessel occlusion. Studies of ours and others have shown thioredoxin-interacting protein (TXNIP) is critically involved in hyperglycemic stroke injury. We recently found verapamil ameliorates cerebrovascular toxicity of tissue plasminogen activators in hyperglycemic stroke. The present study aims to answer if verapamil exerts direct neuroprotective effects and alleviates glucose toxicity following thrombectomy in a preclinical model of hyperglycemic stroke. Primary cortical neural (PCN) cultures were exposed to hyperglycemic reperfusion following oxygen-glucose deprivation (OGD), with or without verapamil treatment. In a mouse model of intraluminal stroke, animals were subjected to 4h middle cerebral artery occlusion (MCAO) and intravenous glucose infusion. Glucose infusion lasted one more hour at reperfusion, along with intra-arterial (i.a.) verapamil infusion. Animals were subjected to sensorimotor function tests and histological analysis of microglial phenotype at 72h post-stroke. According to our findings, glucose concentrations (2.5-20mM) directly correlated with TXNIP expression in OGD-exposed PCN cultures. Verapamil (100nM) effectively improved PCN cell neurite growth and reduced TXNIP expression as well as interaction with NOD-like receptor pyrin domain-containing-3 (NLRP3) inflammasome, as determined by immunoblotting and immunoprecipitation. In our mouse model of extended hyperglycemic MCAO, i.a. verapamil (0.5mg/kg) could attenuate neurological deficits induced by hyperglycemic stroke. This was associated with reduced microglial pro-inflammatory transition. This finding encourages pertinent studies in hyperglycemic patients undergoing thrombectomy where the robust reperfusion may exacerbate glucose toxicity.